Concerning the antileukemic agent jatrophatrione: the first total synthesis of a [5.9.5] tricyclic diterpene

J Am Chem Soc. 2002 Jun 12;124(23):6542-3. doi: 10.1021/ja020292z.

Abstract

The highly functionalized [5.9.5] tricyclic framework resident in jatrophatrione (1) has been synthesized. The route begins with the tandem anionic oxy-Cope rearrangement/methylation/transannular ene cyclization of 5 and subsequent introduction of a conjugated enone double bond. Hydroxyl-directed 1,4-reduction of this functionality in 6 with LiAlH4/CuI/HMPA/THF sets the stage for the implementation of a Grob fragmentation and rapid generation of 8. Stereocontrolled intramolecular hydrosilylation allows for the subsequent introduction of a cyclic carbonate as in 11. This intermediate undergoes a remarkably smooth Treibs reaction to generate 12, thus serving as a pivotal step for making 1 available five steps later.

MeSH terms

  • Antineoplastic Agents, Phytogenic / chemical synthesis*
  • Diterpenes / chemical synthesis*
  • Euphorbiaceae / chemistry
  • Plant Roots / chemistry

Substances

  • Antineoplastic Agents, Phytogenic
  • Diterpenes
  • jatrophatrione